1. Field of the Invention
The disclosure relates to a line scanning measurement system.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
In modern optical technology, birefringence crystals such as waveplates, birefringence prisms, and liquid crystals are important optical components. In general, optical parameters of birefringence crystals such as principal axis, phase retardation/phase difference, refractive index, polarization characteristic and thickness play an important role in optical and biomedical industries. Therefore, it is absolutely important for practical applications and yield rates of optical elements to measure optical parameters accurately.
In the past, measuring systems were often based on single-point detection. Capturing full-field information of a sample requires measuring the sample repeatedly, taking a long time. U.S. Pat. No. 5,521,705 discloses a method for determining polarization properties. A pair of variable retarders is positioned in an optical path with their slow optical axes at a 45° angle to each other. A polarized light analyzer is also placed in the optical path between light retarders and a detector. The method determines the polarization properties of light from the intensities measured at different retardance levels.
U.S. Pat. No. 7,202,950 discloses a method for measuring retardance. A sample is illuminated by circularly polarized monochromatic light which is then analyzed by an elliptical analyzer at different settings. In addition, light conditioned by an elliptical polarizer at various settings illuminates a sample and the beam exiting the sample is analyzed by a circular analyzer.
However, the above-mentioned methods take a long time to measure a sample and set polarization parameters of polarizers repeatedly. Thus, finding a method to build a measurement system which measures characteristic parameters of a large-area sample rapidly is an important issue for the related industries.